The present invention relates to a method and machine for making cigarettes, cigars, cigarillos or analogous rod-shaped smokers' products, and more particularly to a method and machine for making rod-shaped smokers' products (hereinafter called cigarettes for short) of the type wherein a tubular wrapper of cigarette paper or the like surrounds a composite rod-like tobacco filler. Still more particularly, the invention relates to improvements in a method and machine for the manufacture of cigarettes containing several types of natural tobacco or natural tobacco plus other material, such as reconstituted tobacco, a particulate fibrous filler material or another substitute for tobacco.
It is known to manufacture cigarettes, cigars or cigarillos in such a way that the rod-like filler consists of two types of tobacco. Thus, in certain types of presently known cigarettes, the major portion of the rod-like filler consists of tobacco shreds having a relatively high nicotine content and the minor portion of the filler consists of tobacco shreds having a lower nicotine content or of a substitute for tobacco. The minor portion then constitutes a filter plug, i.e., it is placed into the mount and the smoker lights the free end of the major portion of the filler. It is desirable to establish a clear-cut line of demarcation or boundary between the major and minor portions of the rod-like filler (as considered in the axial direction of the cigarette) and to further insure that the boundary is located at a predetermined distance from both ends in each of a series of mass-produced cigarettes.
A drawback of presently known methods and machines for the production of just described cigarettes having composite fillers is that the output is low and that the cigarettes cannot be manufactured with a desired degree of reproducibility (especially as regards the locus of the boundary between the two portions of the filler). Attempts to mass-produce cigarettes of the just described type include the provision of a machine which produces a rod-like filler consisting of overlapping portions having tobacco shreds of different types, i.e., the filler portion having shreds of one type is not placed end-to-end with the filler portion having tobacco shreds of another type. The arrangement is such that the ratio of one type of tobacco shreds to the other type of tobacco shreds varies, as considered in the axial direction of the filler. Reference may be had to German Offenlegungsschrift No. 2,259,814. This publication discloses a machine having means for producing a continuous tobacco stream consisting of tobacco shreds of a first type, means for forming wedge-like cutouts in the stream, and means for inserting tobacco shreds of a second type into successive cutouts to form a composite stream which is thereupon trimmed and wrapped into cigarette paper or the like. Thus, filler portions which contain shreds of the first type taper in the axial direction of the filler, the same as the filler portions containing shreds of the second type. Such machine exhibits the drawback that the smoker is likely to inhale smoke which develops during simultaneous combustion of both types of tobacco shreds. Moreover, then the composite stream is trimmed, the removed surplus contains a mixture of both tobacco types so that the surplus cannot be returned into the magazine for tobacco shreds of the first or second type. Consequently, the operation is wasteful and the smoker is likely to inhale smoke produced on combustion of low-quality tobacco or a substitute therefor.